How do Robot Lawn Mowers Work? | Embrace the Future of Gardening

Robot lawn mowers can be a gardener’s best friend. Especially if you are not willing to spend entire Sunday afternoons trying to make your lawn professionally cut and tidy, you might have already started to wonder how robot lawn mowers work.

No wonder you are a little dubious about these lawnmowers! They promise a lot and, if you are not in the field of technologies, you might be confused about how these machines can be so helpful.

However, be assured that some of the best robot lawn mowers are state-of-the-art pieces of machinery that have developed through history to become highly functional, offering cutting-edge technology, navigation sensors, and even the ability to control them through a smartphone app. 

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How Do Robot Lawn Mower Work?

Using a simple mapping system, robotic mowers can detect where you have laid the perimeter wire around your lawn. As they realize they are approaching it, they will change course and proceed in cutting the grass of your lawn.

Even better, the technology of robot mowers allows them to avoid running multiple times in the same area and therefore leaving unevenly cut patches.

More advanced robot mowers are equipped with a 360-degree radar (sometimes laser) sensor. This allows the machine to identify potential obstacles on the way, increasing the level of safety of your robotic lawn mower.

It seems fairly simple, right? However, they cost a lot of money and there is much more to it that you should know!

What you need to know to understand how robot Lawn Mower Work

Of course, the main task of a lawnmower is to cut the grass. However, robotic lawn mowers use a completely different technology from what you might have seen in a manual lawn mowing machine.

Normal lawnmowers tend to cut the grass much faster and therefore need much a more powerful cutting blade to get the job done quickly and with a limited amount of energy.

These are often also powered by petrol or fuel, which makes them much more powerful and noisy (as well as contributing to pollution and causing damage to the earth). 

However, while robot lawn mower models are designed to be autonomous, you will realize that they get the job done slower, but without the noise. This is mainly due to the size of the spinning blades, the speed they’re mowing at, and the power they are set on. 

While the first might be slightly more efficient, the second makes the mower much quieter as it goes around the required space in your yard.

As a homeowner, it’s up to you to decide which one of these will be most suitable for your house. Consider factors like lawn care, cost, scheduling and control capabilities, and any particular benefits each one has to offer.

For reliable, automated mowing services, individuals should consider robotic mowers for their gardens.

The Chassis And Wheels of your robot lawnmower

As for other similar types of machines, the chassis and wheels of your robot lawn mower are the components of the skeleton of your device. While it can seem a simple construction at first, there are a couple of factors that are taken into consideration and highly increase the efficiency of your robotic mower. 

Firstly, let’s have a look at the wheels of your robot mower. These are designed to be extremely delicate on your grass to avoid damaging lawns while taking care of them. If the mower wasn’t delicate, you would see track marks in no time!

Secondly, aside from ensuring that the wheels work properly, the chassis of your robotic mower is designed to make the machine incredibly safe.

The blades of rotating discs are usually positioned within the chassis, which reduces the chances of accidents while taking care of lawns. It is incredibly difficult to access the grass blades while your robot mowers are powered on! This means that your blades can have a sharp edge without posing a risk.

Lastly, robotic lawn mowers have a low center of gravity and powerful motors allow them to move easily across hills and bumpier terrain with small chances of toppling over.

The resistance of your robot mower is often directly linked to the type of model you have invested in. More expensive versions can drive along considerable gradients of up to 25 degrees and may have a wider cutting width.

The computer system of robot lawnmowers

While it is possible to create incredibly efficient lawn mowers that will cut your grass in no time while being silent and consuming a minimum amount of energy, this would not be affordable in any sense.

That is why most manufacturers opt for compromising. Keeping the computer system of the robot mowers allows the machine to be affordable for anybody.

Among the essential tasks that your robot mower is programmed to execute, you will notice simple commands such as avoiding obstacles, recognising wire boundaries, and mowing the entire lawn.

The most important instructions embedded in the onboard computer of robot mowers are the safety features. These are essentials, as your robotic auto mower will be operating unsupervised for days at a time. 

Robot mowers are able to clean up lawns on their own and have their blades tucked away safely to prevent risk, what more could you ask for in a lawn mower?

How do robotic lawn mowers know where to cut the grass?

As you have bought your robot mower, you would have realized that it needs a perimeter wire to function properly.

Before experimenting with your robot, make sure you have correctly placed the guidewire around the edges of your lawn to create an area where your mower can clean without any issue.

This can take up to 2 hours to be set up properly, depending on how big your garden is. The perimeter wire can also be placed around obstacles and objects on your lawn and buried up to 20cm down in the ground.

If you prefer to leave it on the surface of your grass, make sure it is fixed properly, and don’t worry, it will be invisible once the grass has grown over it.

Random robot lawn mower systems

If you are wondering what to expect after buying your robotic mower, there are a couple of factors to consider. Firstly, lawnmowers are designed to run in a straight line until they recognize an object or the boundary wire. From here, it will either turn around or take up a different direction.

However, depending on how much you are willing to invest in your next robotic lawn mower, you could even own a unit with an integrated GPS system through which you can set specific paths and even patterns throughout the area, negating the need to have boundary wire all over the place. Furthermore, obstacles like flower beds, ponds, or bushes can be excluded and the robot will drive around them.

Battery and Solar Power

Most robot mowers run on standard batteries. However, before choosing the perfect robot for your garden, make sure that the ones mounted on it are lithium rather than classic acid ones.

In fact, the first ones only take about 3 hours to be fully charged, while the second ones can take up to 16!

Even though most manufacturers are swapping to lithium, some cheaper and older models still run on acid ones. If you find one that has rechargeable batteries, make sure it comes with a charging station.

Alternatively, since 1995, it is possible to find fully solar-powered robot mowers, which have then been perfected since 2004. These are even better for both you and the planet!

Once charged your robot mower will head off to start trimming the tall grass on your lawn. As the battery drops, it will return to the charging station before heading off again to cut any grass it left. You really don’t need to get involved.

Robotic Lawn Mower: what to look out for!

If you are searching for your first robot mower and you are not yet willing to invest an incredible amount of money to have an integrated remote control system, and GPS system in your robot, perimeter wires may need as much maintenance as the lawn mowing robot itself.

Breakage can happen due to freezing conditions, burrowing animals, or just expositions to natural elements. Alternatively, you might just want to change up the shape of your garden.

If that’s the case, picking up the boundary wire lines can be quite quick if you have buried them, or you are not sure where it is precisely.

They can be great to define an area or pattern to be mowed, but as you can see the perimeter wire technology does have its weaknesses.


How do Robot Lawn Mowers recharge?

All robot mowers come with a rechargeable, electric battery pack that is replenished at a docking station. The entire process is automated, so when the battery gets too low the mower will automatically head back to the recharging station.

Do Robot Lawn Mowers work in the rain?

Yes. Unlike us, robot mowers don’t mind if it’s pouring rain outside. They are designed to operate in all sorts of weather conditions, with the only exceptions being very blustery storms or sub-zero conditions. During these times you’re better off moving your machine indoors to avoid damage.

How long do Robot Mowers operate?

Again, depending on your machine, these robot mowers can last 10 years. Although with proper maintenance and care you can really extend the lifespan.

Do Robot Mowers collect grass?

As mentioned above, all mowers are actually mulching mowers. Instead of gathering up the grass as they go, they re-distribute the small clippings back onto the lawn. This Is great for the garden as your return nutrients back into the soil naturally. The robot lawn mower cuts continuously, clipping small portions of the leaf blade more often than the typical homeowner who might cut grass on the weekend.

How do Robot Lawn Mowers navigate?

Depending on your model, robot mowers utilize guide wires that the user lays around the perimeter of their garden, the mower will then cut inside these lines. Other models can come equipped with an onboard GPS which will create a digital map of the lawn.


About the author

Matt is the founder of the Little Robot Shop, who has spent much of the last decade hacking home cleaning with various robots and devices to make keeping his home clean as easy as possible. Not an easy task with two young children.

When not working on the Little Robot Shop website or YouTube channel, he works as technical support and product specialist for a fast-growing digital company. He does his best to get his younglings to code, which will be an essential skill in the future.

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